package org.zero.utils;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * @Author Zero
 * @Description
 * @Date 2021/6/26 23:11
 * @Since 1.8
 **/
public class CheckUtil {
        // 与接口配置信息中的Token要一致
        private static String token = "zerocl";

        /**
         * 验证签名
         *
         * @param signature
         * @param timestamp
         * @param nonce
         * @return
         */
        public static boolean checkSignature(String signature, String timestamp, String nonce) {
            String[] arr = new String[] { token, timestamp, nonce };
            // 将token、timestamp、nonce三个参数进行字典序排序
            // Arrays.sort(arr);
            sort(arr);
            StringBuilder content = new StringBuilder();
            for (int i = 0; i < arr.length; i++) {
                content.append(arr[i]);
            }
            MessageDigest md = null;
            String tmpStr = null;

            try {
                md = MessageDigest.getInstance("SHA-1");
                // 将三个参数字符串拼接成一个字符串进行sha1加密
                byte[] digest = md.digest(content.toString().getBytes());
                tmpStr = byteToStr(digest);
            } catch (NoSuchAlgorithmException e) {
                e.printStackTrace();
            }
            content = null;
            // 将sha1加密后的字符串可与signature对比，标识该请求来源于微信
            return tmpStr != null ? tmpStr.equals(signature.toUpperCase()) : false;
        }

        /**
         * 将字节数组转换为十六进制字符串
         *
         * @param byteArray
         * @return
         */
        private static String byteToStr(byte[] byteArray) {
            String strDigest = "";
            for (int i = 0; i < byteArray.length; i++) {
                strDigest += byteToHexStr(byteArray[i]);
            }
            return strDigest;
        }

        /**
         * 将字节转换为十六进制字符串
         *
         * @param mByte
         * @return
         */
        private static String byteToHexStr(byte mByte) {
            char[] Digit = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
            char[] tempArr = new char[2];
            tempArr[0] = Digit[(mByte >>> 4) & 0X0F];
            tempArr[1] = Digit[mByte & 0X0F];
            String s = new String(tempArr);
            return s;
        }
        public static void sort(String a[]) {
            for (int i = 0; i < a.length - 1; i++) {
                for (int j = i + 1; j < a.length; j++) {
                    if (a[j].compareTo(a[i]) < 0) {
                        String temp = a[i];
                        a[i] = a[j];
                        a[j] = temp;
                    }
                }
            }
        }
}
